Field of the Invention
The present application relates to pressure conditioning apparatuses for surgical insufflation systems and more particularly to pressure conditioning apparatuses to maintain a substantially constant pressure at a surgical site despite pulsing or discontinuous insufflation supply and leakage and absorption at the surgical site.
Description of the Related Art
During Trans Anal Minimally Invasive Surgery (TAMIS) an insufflation machine is used to inflate the rectum with an insufflation gas such as carbon dioxide (CO2). The inflation allows room for a surgeon to perform a surgical procedure using laparoscopic instruments and techniques. Many insufflation machines provide CO2 in pulses, alternating pressurization pulses with pressure measurements. The colorectal system, however, is not a sealed volume and CO2 continuously leaks from the inflated surgical area causing the pressure to drop. Additionally, CO2 is readily absorbed by the walls of the colorectal system thereby exacerbating the loss of pressure caused by the leakage. CO2 can leak from the system through a variety of leak paths, ranging from the length of the colorectal system, absorption by the intestine/colorectal walls, and through the surgical instruments and tools used to gain access. At some points of the procedure, a smoke evacuation port is constantly open in order to encourage the flow of CO2, forcing out smoke generated by electrocautery. The multitude of leak paths leads to a loss of pressure and pulsed insufflation flow manifests itself as billowing of the rectal walls. The billowing follows the pressure cycle from the insufflation machine: when the machine is providing CO2 pressure the rectal walls expand and when the insufflation machine is not supplying pressure (measuring the pressure) the rectal walls contract. The movement of the rectal walls can make laparoscopic surgery more difficult during a TAMIS, or other transanal procedure, which can require manipulation of and treatment of growths on the rectal walls.